object CollectionOpsDemo {
  def main(args: Array[String]): Unit = {
    val clubs = List(
      ("编程社", 35),
      ("文学社", 28),
      ("篮球社", 42),
      ("话剧社", 25),
    )
    val activeClubs = clubs.filter { case (_, count) => count >= 30 }
    val clubFormats = activeClubs.map { case (name, count) =>
      s"$name($count 人)"
    }
  println("活跃社团:")
  clubFormats.foreach(println)
 }
}
